JPS6319462A - Centrifugal hydraulic pressure correcting device for belt type continuously variable transmission - Google Patents

Abstract

PURPOSE:To prevent the shortage of pump capacity in idling, etc. by installing a balance valve between the hydraulic chamber and balance chamber of a secondary pulley and correcting the centrifugal hydraulic pressure by supplying oil into the balance chamber. CONSTITUTION:When the primary hydraulic pressure is increased by the rise of the car speed, the transmission shifts to the high speed stage side, and also the revolution speed of a secondary pulley 37 increases, and a centrifugal hydraulic pressure is generated in the oil supplied into a hydraulic chamber 55. As the speed change ratio shifts to the high speed stage side, the line pressure lowers, and the check ball 65 of a balance valve 60 is easily opened, and also the centrifugal force of the check ball 65 itself increases. Therefore, at a prescribed secondary revolution speed, the check ball 65 shifts outside from the center of a tapered part 63a overwhelming the pressing force of the line pressure by the centrifugal force, and an oil passage 64 is opened, and the centrifugal hydraulic pressure is corrected, and the shortage of pump capacity can be prevented.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a centrifugal hydraulic pressure correction device for correcting centrifugal hydraulic pressure generated in a cylinder of a secondary pulley in a high rotation range in a belt-type continuously variable transmission for a vehicle. This type of belt-type continuously variable transmission has a drive belt wrapped around a brake pulley on the engine side and a secondary pulley on the wheel side, and each pulley's movable pulley is equipped with a hydraulic servo mechanism. Then, the movable boot is hydraulically moved in the axial direction to adjust the boob spacing, and the diameter ratio of the winding of the secondary pulley around the briny pulley of the belt is changed to achieve non-G speed shifting. Therefore, the secondary pulley speeds up as the gear shift progresses to higher speed stages, and during overdrive, the speed increases by a maximum of 2 to 3 times the primary rotation speed. Therefore, the hydraulic pressure inside the cylinder of the secondary pulley is similarly rotated at high speed, and at this time, centrifugal hydraulic pressure is generated, which additionally acts on the secondary pulley separately from the secondary hydraulic pressure. Thus, there is a problem in that this centrifugal oil pressure moves the secondary pulley back to the low speed side when shifting to the 8th speed side, and generates an excessive boob pressing force during overdrive.

[Conventional technology]

Conventionally, correction devices have been proposed as a countermeasure to the problem of centrifugal hydraulic pressure. This is done by providing a hydraulic chamber on one side of the plunger and a balance chamber on the opposite side inside the cylinder of the secondary pulley. Then, an orifice is provided in the plunger to leak part of the secondary hydraulic pressure from the hydraulic chamber and supply it to the balance chamber, or
As shown in Japanese Patent No. 104848, oil is supplied to each balance chamber separately by an oil guide plate or an oil passage. In this way, the centrifugal hydraulic pressure generated in the hydraulic chamber in the high rotation range is offset by the centrifugal hydraulic pressure in the balance chamber.

[Problems to be solved by the invention]

By the way, regarding the method of supplying oil to the balance chamber, the prior art method using an orifice stops oil leakage even when the oil pump is at its lowest efficiency, such as when idling or in the low rotation range, so the pump capacity must be increased accordingly. ,
Further, according to the latter prior art, the structure is double-sided and dedicated holes are formed in the axial and radial directions of the shaft, which is unfavorable in terms of workability and strength. For this reason, it is desirable to accurately supply oil to the balance chamber in the high rotation range where the influence of the centrifugal oil pressure of the secondary pulley becomes large, and to simplify the oil supply means so as not to affect other parts. The present invention has been made in view of these points, and is a belt-type continuously variable transmission that has a simple configuration and performs oil supply to the balance chamber only in a high rotation range so as not to increase the pump capacity. The purpose is to provide a centrifugal hydraulic correction device for machines.

[Means to solve problems] In order to achieve the above object, the present invention provides a configuration in which a hydraulic chamber on one side of a plunger that fits inside the cylinder of a secondary pulley is provided with a balance chamber for centrifugal hydraulic pressure correction on the opposite side. It is configured to include a balance valve that opens and closes depending on the relationship between centrifugal force and pressing force of line pressure. [For production]

Based on the above configuration, the balance valve closes in idle link and low speed ranges to prevent oil leakage, and opens only in high speed ranges above the predetermined secondary rotation speed to supply oil to the balance chamber and correct centrifugal oil pressure. I come to do it. In this way, in the present invention, oil leakage does not occur in the idle link and low rotation ranges where the influence of centrifugal oil pressure is small, so there is a surplus in the amount of oil in this case, and it is possible to prevent an increase in pump capacity.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. In FIG. 1, an example of a belt type continuously variable transmission to which the present invention is applied will be described. Reference numeral 1 is an electromagnetic powder clutch, 2 is a continuously variable transmission, and the continuously variable transmission 2 can be broadly classified into: J reverse switching section 3 from the input side. The boolean ratio converting section 4 and the final reduction section 5 are configured in a transmission configuration. and,
m on one side of the clutch housing 6! A powder type clutch 1 is housed in 4, and inside the other side of the clutch housing θ, a main case 7 joined thereto, and a side case 8 joined to the side opposite to the clutch housing 6 of the main case 7, Switching section 3 of continuously variable transmission 2. A boolean ratio conversion section 4 and a final reduction section 5 are assembled. The electromagnetic powder clutch 1 is connected to the crankshaft 10 from the engine.
A ring-shaped drive member 12 is integrally connected to the drive plate 11 via the drive plate 11. It has a disk-shaped driven member 14 that is integrally spline-coupled to the transmission input shaft 13 in the rotational direction. A coil 15 is built into the outer peripheral side of the driven member 14, and a gap 16 is formed along the circumference between both members 12.14.
communicates with a powder chamber 17 containing electromagnetic powder inside thereof. Further, a power feeding brush 19 is in sliding contact with a slip ring 18 of the hub portion of the driven member 14 including the coil 15, and from the slip ring 18, the driven member 14 is further attached.
A clutch current circuit is configured by passing through the inside and being connected to the coil 15. In this way, when the clutch current is passed through the coil 15, the po,
Drive and Tribe member 12.1 via
4, electromagnetic powder is combined and accumulated in the gap 16 in a chain shape, and the resulting binding force causes the driven member 14 to slide and integrally connect to the drive member 12, resulting in a clutch connected state. . On the other hand, when the clutch current is cut, the drive by electromagnetic powder and the coupling force between the driven members 12 and 14 disappear, resulting in the clutch being in a bright state. Then, the control of the clutch current in this case is controlled by continuously variable speed R2.
If this is done in conjunction with the operation of the switching unit 3, it is possible to switch from P (parking) or N to neutral) range to forward D.
(Drive), Ds<Sporty Drive) or when switching to the R (Reverse) range for reverse, clutch 1 is automatically engaged, eliminating the need for clutch pedal operation. Next, in the continuously variable transmission 2, the switching section 3 connects the input shaft 13 from the clutch 1 and the main shaft 2 disposed coaxially therewith.
0. That is, the input shaft 13 is formed with a reverse drive gear 21 that also serves as a forward inspection target side, and a reverse drive engaged side gear 22 is rotatably fitted to the main shaft 20. .22 is the counter gear A724 supported by the shaft 23, and the idler gear 2 supported by the shaft 25.
They are meshed through 6. A switching machine MA27 is provided between the main shaft 20 and the gears 21 and 22. Here, the gears 21, 24, 26, 22 that are always engaged are the coil 15 of the clutch 1.
The switching device v821 has a sleeve 29 spline-fitted to the hub 28 of the main shaft 20, which is connected to the driven member 14 having a synchronizing mechanism. 30° 31 to mesh with each gear 21, 22. As a result, in the neutral position of the P or N range, the sleeve 29 of the switching mechanism 27 is fitted only with the hub 28, and the main shaft 2
0 is disconnected from the input shaft 13. Next, the sleeve 29
When meshed with the gear 21 side via the synchronization mechanism 30,
The main shaft 20 is directly connected to the input shaft 13, resulting in a forward movement state in the D or Dδ range. On the other hand, when the sleeve 29 is reversely engaged with the gear 22 side via the synchro mechanism 31, the input shaft 13 is connected to the main shaft 20 via the gears 21, 24, 26, 22, the engine power is decelerated and reversed, and the R The range will move backwards. In the boolean ratio conversion unit 4, an n1 shaft 35 is arranged parallel to the main shaft 20, and primary pulleys 36. The secondary pulley 37 is twisted by 8°, and the endless drive belt 34 is looped between both pulleys 36 and 37. The pulleys 36 and 37 are each divided into two parts, one of which is a fixed pulley 36a. With respect to 37a, the other movable pulleys 36b and 37b are made movable so that the pulley interval is variable (the movable pulley 36
Hydraulic servo devices 38 and 39 that also serve as pistons are attached to the movable pulleys 37b and 37b of the secondary pulley 37, and a spring 40 is applied to the movable pulley 37b of the secondary pulley 37 in the direction of narrowing the boe spacing. Further, as a hydraulic control system, an oil pump 41 as an operating source is installed next to the primary pulley 36. This oil pump 41 is a high-pressure gear A2 pump, and the pump drive shaft 42 is connected to the primary pulley 36. Spindle 20 and input! ?
! ! 113 and is directly connected to the crankshaft 1o,
Hydraulic pressure is generated during engine operation. Then, the oil pressure of this oil pump 41 is controlled to supply and drain oil to each hydraulic servo device 38, 39, and the primary pulley 36
By changing the pulley opening distance of the secondary pulley 37 to the opposite relationship, the pulley ratios of the pulleys 36 and 37 of the drive belt 34 are changed steplessly, and steplessly variable power is output to the subshaft 35. The final reduction unit 5 has a high-speed stage side minimum boolean ratio of the boolean conversion unit 4 that is very small, for example, 0.5, and therefore the rotation speed of the DJ shaft 35 is high. Output N144 is connected via one set of intermediate reduction gears 43. A final gear 4G meshes with the drive gear 45 of the output shaft 44, and transmission is configured to be transmitted to the axles 48 and 49 of the left and right drive shafts via the final gear 46 and the differential mechanism 47. In FIG. 2 (2), the hydraulic servo device 39 of the secondary pulley 37 will be described in detail.A movable pulley 37b is fitted onto the subshaft 35 so as to be movable in the axial direction via a ball spline 50. One end of a cylindrical cylinder 51 is attached. Further, one end of the plunger 1-52, which has a stepped cylindrical shape, is integrally fixed to the subshaft 35 by a fitting 53, and the other end of the plunger 52 is sealed inside the cylinder 51 with an O-ring 54, and the liquid is Closely fitted. Inside the cylinder 51, a hydraulic chamber 55 is formed on the boob side of the plunger t-52, and a balance chamber 56 is formed on the opposite side.
5. Line pressure is supplied through the passage 557 of the movable pulley 37b. Furthermore, the plunger 52
A balance valve 60 is attached to the vertical portion 52a. The balance valve 60 will be described with reference to σ5 in FIG. The valve body 61 has a hole 63 inside, and a tapered portion 63 a communicates with an oil passage 64 . A check ball 65, which is a valve body and also serves as a weight, is provided in the tapered portion 63a, and a stop ring 6 is provided in the hole 63.
6. A wave-shaped spring 67 is attached. Next, the operation of the centrifugal hydraulic pressure correction device configured as described above will be explained. First, line pressure is always supplied to the hydraulic chamber 55 of the secondary pulley 37, and the boob is pressed.In idling or low rotation range, the primary hydraulic pressure is small, so the belt 34 is forced to move as shown in Fig. 1. It turns into low gear. At this point, the line pressure is set high as shown in FIG. 3 in accordance with the transmitted torque, and this line pressure is applied to the hydraulic chamber 55.
This also acts on the check ball 65 of the balance valve 60 to make it easier to close. Furthermore, since the rotational speed of the secondary pulley 37 is low due to the gear ratio of the low speed stage, the centrifugal force acting on the check ball 65 is also small. Therefore, the check ball 65 is located at the center of the tapered portion 63a and closed, and the balance chamber 56 is no longer supplied with oil. Next, when the primary oil pressure decreases due to the upper limit of the vehicle speed, the belt 34 begins to wrap around the movable pulley 37b in the secondary pulley 37 while moving backward, thereby shifting to the high speed side. Therefore, the rotational speed of the secondary pulley 37 also increases, and centrifugal oil pressure starts to be generated in the oil supply of the hydraulic chamber 55. On the other hand, as the gear ratio shifts to the high speed side, the line pressure decreases as shown in FIG. 3, so that the check ball 65 of the balance valve 60 opens more easily, and the centrifugal force of the check ball 65 itself increases. Therefore, the check ball 65 is rotated at a predetermined secondary rotation speed.
overcomes the pressing force of the line pressure due to centrifugal force and moves outward from the center of the tapered portion 63a as shown by the dashed line in FIG. Therefore, a portion of the oil in the hydraulic chamber 55 is immediately supplied to the balance chamber 56, and a centrifugal hydraulic pressure approximately equal to the centrifugal hydraulic pressure in the hydraulic chamber 55 is similarly generated. By applying this hydraulic pressure in the opposite direction to the secondary pulley 37 of the cylinder 51, the centrifugal hydraulic pressure in the hydraulic chamber 55 is offset. On the other hand, since the check ball 65 is pressed against the wave-shaped spring 67 at this time, when the secondary rotation speed decreases, the restoring force of the spring 67 is also added, and the check ball 65 is again closed. Referring to d3 in FIG. 4, another embodiment of the balance valve 60 will be described. A through hole 63' is provided in the radial direction perpendicular to the oil passage 64, and a solid valve body 65- is inserted into the hole 63'.
is inserted to open and close the oil passage 64. A spring 67- is biased on the radially outer side of the valve body 65-, and its inner closed position is set by a pin 68, and thus opens and closes by centrifugal force in the same manner as described above. A similar effect can be obtained by using two check balls 70 and 70 instead of the valve body 65-. Although the embodiments of the present invention have been described above, the present invention is not limited thereto.

【Effect of the invention】

As described above, according to the present invention, a balance valve is provided in the plunger between the hydraulic chamber and the balance chamber of the secondary pulley, and the balance chamber is supplied with oil only when the number of rotations of the secondary pulley is higher than or equal to a predetermined number of revolutions, thereby increasing the centrifugal hydraulic pressure. Since the configuration corrects for this, it is possible to avoid insufficient pump capacity in idle links, etc., which have the lowest pump efficiency. Since the system leaks oil from the hydraulic chamber to the balance chamber, there is no need for complicated oil supply means. Since the balance valve is configured to open and close based on the pressing force relationship between centrifugal force and line pressure, the secondary rotation speed at which the balance valve opens can be appropriately determined to sufficiently compensate for centrifugal oil pressure in the high rotation range.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an example of a belt type continuously variable transmission to which the present invention is applied, FIG. b) is an enlarged sectional view of the same, FIG. 3 is a line pressure characteristic diagram, and FIGS. 4 and 5 are sectional views showing other embodiments of the present invention. 2...Continuously variable transmission, 4...Boot ratio conversion section, 37.
...Secondary pulley, 39...Hydraulic servo device, 5
1...Cylinder, 52...Plunger, 55...
Hydraulic chamber, 56...Balance exchange, 60...Balance valve, 61...Valve body, 64...Oil passage, 65, 65--
... Valve body, 67, 67-... Spring. Patent Applicant Fuji Heavy Industries Co., Ltd. Agent Patent Attorney Nobu Kobashi Ukiyo Patent Attorney Shinyoshi Murai 3 Takashi 4 Fig. 5

Claims (2)

[Claims] (1) In a configuration in which a hydraulic chamber on one side of the plunger that fits inside the cylinder of the secondary pulley is provided with a balance chamber for centrifugal hydraulic pressure correction on the opposite side, the pressing force of centrifugal force and line pressure is applied to the plunger. A centrifugal hydraulic correction device for a belt-type continuously variable transmission that is equipped with a balance valve that opens and closes depending on the relationship. (2) The balance valve mentioned above consists of a valve body attached to a plunger, an oil passage that communicates both chambers, a valve body that also serves as a weight and opens the oil passage at a predetermined secondary rotation speed or more, and a direction in which the oil passage of the valve body is closed. The centrifugal hydraulic correction device for a belt-type continuously variable transmission according to claim 1, further comprising a return spring that biases the centrifugal hydraulic pressure correction device for a belt type continuously variable transmission.